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package projecteuler;
import java.math.BigInteger;
/**
 *
 * @author ChunchO
 */


public class Problem025 {
		public static void main(String[] args) {

			BigInteger F0 = BigInteger.ONE;
			BigInteger F1 = BigInteger.ONE;
			int number = 2;
			boolean done = false;
			while(!done)
			{
				BigInteger F2 = F0.add(F1);
				F0 = F1;
				F1 = F2;
				number++;
				if(F2.toString().length()>=1000)
					done = true;
			}
			System.out.println(number);
		}
}
